MHD phenomena in reversed shear plasmas in TFTR are described during each of the three phases of the evolution of these discharges: the current ramp, high power neutral beam heating and after the beam power has been reduced. Theoretical analysis of discharges which disrupted in the high-{beta} phase indicates that the {beta} - limit is set by the ideal n = 1 infernal/kink mode. The mode structure of the disruption precursor reconstructed from the electron temperature data compares favorably with the predicted displacement vector from the ideal MHD model. In contrast, disruptions during the early and late phases are due …
continued below
Serving as both a federal and a state depository library, the UNT Libraries Government Documents Department maintains millions of items in a variety of formats. The department is a member of the FDLP Content Partnerships Program and an Affiliated Archive of the National Archives.
Descriptive information to help identify this article.
Follow the links below to find similar items on the Digital Library.
Description
MHD phenomena in reversed shear plasmas in TFTR are described during each of the three phases of the evolution of these discharges: the current ramp, high power neutral beam heating and after the beam power has been reduced. Theoretical analysis of discharges which disrupted in the high-{beta} phase indicates that the {beta} - limit is set by the ideal n = 1 infernal/kink mode. The mode structure of the disruption precursor reconstructed from the electron temperature data compares favorably with the predicted displacement vector from the ideal MHD model. In contrast, disruptions during the early and late phases are due to resistive instabilities, double tearing modes coupled to high-m edge modes. The resistive interchange mode, predicted to be unstable in reversed shear plasmas, is not seen in the experiment. Neo-classical tearing mode theory is shown to describe the non-disruptive MHD phenomena. A nonlinear resistive MHD simulation reproduces off-axis sawtooth-like crashes during the post-beam phase. The dependence of the {beta}-limit on the pressure peakedness and q{sub min} is discussed, showing a path to stable higher-{beta} regimes.
16. International Atomic Energy Agency (IAEA) international conference on plasma physics and controlled nuclear fusion research, Montreal (Canada), 7-11 Oct 1996
This article is part of the following collection of related materials.
Office of Scientific & Technical Information Technical Reports
Reports, articles and other documents harvested from the Office of Scientific and Technical Information.
Office of Scientific and Technical Information (OSTI) is the Department of Energy (DOE) office that collects, preserves, and disseminates DOE-sponsored research and development (R&D) results that are the outcomes of R&D projects or other funded activities at DOE labs and facilities nationwide and grantees at universities and other institutions.
Manickam, J.; Fredrickson, E. & Chang, Z.MHD stability studies in reversed shear plasmas in TFTR,
article,
December 31, 1996;
Princeton, New Jersey.
(https://digital.library.unt.edu/ark:/67531/metadc696342/:
accessed April 25, 2024),
University of North Texas Libraries, UNT Digital Library, https://digital.library.unt.edu;
crediting UNT Libraries Government Documents Department.